Validation of Cryo-Compressed Hydrogen Storage (CCH2) – A Probabilistic Approach

Due to its promising potential to overcome the challenge of thermal endurance of liquid hydrogen storage systems cryo-compressed hydrogen storage (CcH2) is regarded as a verypromising physical storage solution, in particular for use in larger passenger vehicles with high energy and long range requirements. A probabilistic approach for validation of safe operation of CcH2 storage systems under automotive requirements and experimental results on life-cycle testing is presented. The operational regime of BMW's CcH2 storage covers pressures of up to 35 MPa and temperatures from +65 C down to -240 C, applying high loads on composite and metallic materials of the cryogenic pressure vesselcompared to ambient carbon fiber reinforced pressure vessels. Thus, the proof of fatigue strength under combined pressure and deep temperature cyclic loads remains a challenging exercise. Furthermore, it will be shown that the typical automotive safety and life-cycle requirements can be fulfilled by the CcH2 vehicle storage system and, moreover, that the CcH2 storage system can even feature safety advantages over a CGH2 storage system, mainly due to the advantageous thermodynamic properties of cryogenic hydrogen, the lower storage pressure, and due to the intrinsic protection against intrusion through the double-shell design.